2,489 research outputs found
Observations on the Air-Serum Interface of Milk Foams
A new rapid method for the preparation of milk foams for transmission electron microscopy is described . The air-serum interface of foams made from skimmed milk consists of a uniform electron dense layer (5 nm thick) to which casein micelles become secondarily attached . Changes in bubble volume lead to the formation of folds of excess interfacial material which project into the aqueous phase. Using collapsed bubble ghosts to study the attachment of micelles to the airserum interface it was concluded that neither disulphide bridge formation nor hydrophobic interactions were of major importance. Similar preparations of interfacial material but without casein micelles attached were prepared from milk plasma and solutions of ~- lactoglobulin. The former fragmented slowly into small particles at room temperature but very rapidly when heated to 55° C whereas material derived from~- lactoglobulin was quite stable. The destruction of bubble ghosts in skimmed milk by heating is attributed to interface breakdown rather than to micelle detachment. The air-serum interface, of which casein micelles do not form an integral part, probably consists of a mixture of globular whey proteins and some soluble caseins . Thus, using high pressure liquid chromatography, foamed milk plasma from which bubble ghosts had been removed was shown to be depleted in both a- lactalbumin and ~- lactoglobulin
Recent Developments in the Application of X-ray Microanalysis to the Study of Food Systems
Low temperature scanning electron microscopy in conjunction with X-ray microanalysis can be used to study not only the internal structure of intact bulk food systems but also the distribution of their constitutive chemical elements. However, the considerable practical problems that are usually encountered when performing X-ray analysis on frozen samples include: a) the controlled deposition of a good quality carbon film to prevent charging, b) producing digital elemental distribution maps of elements whose X-ray spectral energy peaks partially or completely overlap and c) controlling the plane of fracture through the specimen and ensuring that the resulting topography allows meaningful analysis to be performed.
The quality and control of carbon film deposition is greatly improved by the inclusion of a turbomolecular pump in the vacuum system and by using thickness monitoring of the carbon film during deposition. However, the complications of energy peak overlap in digital X-ray mapping can only be overcome by using a procedure which produces maps corrected for all of the spectrum processing routines normally available in quantitative programmes. Another advantage of this approach is that statistics such as FIT index {see appendix) and standard deviation are available for each pixel.
Problems associated with fracturing are avoided if the internal structure of materials is revealed using cryo-mi11ing. This procedure uses a rotating diamond cutting tool to produce a very flat surface on the frozen specimen which is ideal for X-ray analysis and for image analysis of structural components. Quantitative X-ray mapping of milled cocoa beans shows that this preparation procedure does not cause smearing of the chemical components across the surface of the specimen
Alien Registration- Brooker, Wallace E. (Wade, Aroostook County)
https://digitalmaine.com/alien_docs/32593/thumbnail.jp
The Crystallization of Calcium Phosphate at the Surface of Mould-Ripened Cheeses
Samples of several different types of mouldripened cheese were examined by light and electron microscopy for evidence of calcium phosphate crystallization near their surfaces , which, it was predicted , should result from the pH changes that take place in the rind during ripening . Transmission electron microscopy showed that characteristic convoluted crystals appeared in the rind as mould growth developed and that there was good evidence that at least some of the crystal nucleation was taking place inside effete hyphae. Light microscopy showed that this coincided with the appearance of birefringent, phosphate-rich crystals in the cheese rind which were tentatively identified as calcium phosphate. This was confirmed by a ser ies of experiments in which frozen and fractured cheese was examined by scanning electron microscopy in conjunction with digital X-ray spectrometry . This showed that the rind contained very high levels of calcium and phosphorus which could not be attributed to surface drying because in the same area, there was no corresponding concentration of other elements, such as chlorine.
It is proposed that the high pH generated by the surface flora causes the precipitation of calcium phosphate from the continuous aqueous phase . In addition, the inhibitory effect of casein on the phase transformation to crystalline calcium phosphate is probably removed by the action o f extracellular proteases from the mould. The resulting depletion of calcium phosphate in the aqueous phase establishes a gradient which is responsible for the diffusion of more of the salt from deeper parts of the cheese and the progressive concentration in the rind
HOUSEHOLD NUTRIENT DEMAND: USE OF CHARACTERISTICS THEORY AND A COMMON ATTRIBUTE MODEL
A characteristics model, which assumes goods generate a common set of attributes but no unique attribute, is described. The model yielded two equations which were estimated. One was a set of hedonic price equations in which the price paid for each food purchased was a function of imputed attribute prices. This set of equations was estimated at the household level. Nutrient demand equations were estimated across households. Imputed prices, income, and household characteristics including location, size, education, age distribution, and race affected nutrient demand levels.Consumer/Household Economics,
Incorporating patient preferences in the management of multiple long-term conditions: is this a role for clinical practice guidelines?
Background: Clinical practice guidelines provide an evidence-based approach to managing single chronic conditions, but their applicability to multiple conditions has been actively debated. Incorporating patient-preference recommendations and involving consumers in guideline development may enhance their applicability, but further understanding is needed. Objectives: To assess guidelines that include recommendations for comorbid conditions to determine the extent to which they incorporate patient-preference recommendations; use consumer-engagement processes during development, and, if so, whether these processes produce more patient-preference recommendations; and meet standard quality criteria, particularly in relation to stakeholder involvement. Design: A review of Australian guidelines published from 2006 to 2014 that incorporated recommendations for managing comorbid conditions in primary care. Document analysis of guidelines examined the presence of patient-preference recommendations and the consumer-engagement processes used. The Appraisal of Guidelines for Research and Evaluation instrument was used to assess guideline quality. Results: Thirteen guidelines were reviewed. Twelve included at least one core patient-preference recommendation. Ten used consumer-engagement processes, including participation in development groups (seven guidelines) and reviewing drafts (ten guidelines). More extensive consumer engagement was generally linked to greater incorporation of patient-preference recommendations. Overall quality of guidelines was mixed, particularly in relation to stakeholder involvement. Conclusions: Guidelines do incorporate some patient-preference recommendations, but more explicit acknowledgement is required. Consumer-engagement processes used during guideline development have the potential to assist in identifying patient preferences, but further research is needed. Clarification of the consumer role and investment in consumer training may strengthen these processes.Journal of Comorbidity 2015;5(1):122–13
Travel-Associated Salmonella mbandaka Sacroiliac Osteomyelitis in a Healthy Adolescent.
Pyogenic infections of the sacroiliac joint are rare and usually caused by Staphylococcus aureus. We describe a case of a 16 year-old gymnast who was subsequently diagnosed with Salmonella mbandaka sacroiliac osteomyelitis with adjacent psoas abscess and hepatitis one week after returning from a holiday in Crete. This case highlights a rare presentation of a common travel-associated foodborne infection
Civil society participation in the Scottish marine planning process and the role of Environmental Non-Governmental Organisations
Sustainable development principles are based on the fundamental recognition of humans as an integral part of the ecosystem. Participation of civil society should therefore be central to marine planning processes and enabling ecosystem-based management, and development of mechanisms for effective participation is critical. To date, little attention has been given to the role of Environmental Non-Governmental Organisations (ENGOs) in public participation. In this paper, the results of two workshops, which involved various stakeholders and addressed public participation in marine planning, are reported and discussed in the context of the Scottish marine planning process. ENGOs’ role in communicating complex policies, representing members’ interests and contributing towards participatory governance in marine planning is highlighted. Innovative outreach methods are still required by decision-makers to translate technical information, integrate local knowledge, improve public representation and conserve resources. This could include collaboration with ENGOs to help promote public participation in decision-making processes
How effective is school-based deworming for the community-wide control of soil-transmitted helminths?
Background: The London Declaration on neglected tropical diseases was based in part on a new World Health Organization roadmap to “sustain, expand and extend drug access programmes to ensure the necessary supply of drugs and other interventions to help control by 2020”. Large drug donations from the pharmaceutical industry form the backbone to this aim, especially for soil-transmitted helminths (STHs) raising the question of how best to use these resources. Deworming for STHs is often targeted at school children because they are at greatest risk of morbidity and because it is remarkably cost-effective. However, the impact of school-based deworming on transmission in the wider community remains unclear.
Methods: We first estimate the proportion of parasites targeted by school-based deworming using demography, school enrolment, and data from a small number of example settings where age-specific intensity of infection (either worms or eggs) has been measured for all ages. We also use transmission models to investigate the potential impact of this coverage on transmission for different mixing scenarios.
Principal Findings: In the example settings <30% of the population are 5 to <15 years old. Combining this demography with the infection age-intensity profile we estimate that in one setting school children output as little as 15% of hookworm eggs, whereas in another setting they harbour up to 50% of Ascaris lumbricoides worms (the highest proportion of parasites for our examples). In addition, it is estimated that from 40–70% of these children are enrolled at school.
Conclusions: These estimates suggest that, whilst school-based programmes have many important benefits, the proportion of infective stages targeted by school-based deworming may be limited, particularly where hookworm predominates. We discuss the consequences for transmission for a range of scenarios, including when infective stages deposited by children are more likely to contribute to transmission than those from adults
The Adsorption of Crystalline Fat to the Air-Water Interface of Whipped Cream
The interfacial structure of air bubbles in normal and defective whipped creams were compared, using freeze fracturing and transmission electron microscopy , in an attempt to understand the underlying mechanism of t he observed gross differences in their whipping times and overruns . In normal whipped creams sparsely distributed fat crystals were found to have penetrated some of the bubbles and were lying in the plane of the air/water interface.
In defective whipped creams , large numbers of needle-like crystals had penetrated the air/water interface of every bubble and, as a consequence, reduced numbers of fat globules were found to have adsorbed . There was also morphological evidence that the crystals reached the interface before the milk fat globules during the whipping process . The presence of large masses of free fat in the aqueous phase of whipped cream, on whose surface arrays of very long fat crystals were found, suggested that the needle-like crystals were dislodged by the shear forces generated during whipping and were then free to adsorb to bubbles . The detection of such large amounts of free fat indicated a large scale damage to fat globules during processing with the consequent escape of both crystalline and liquid fat.
Possible mechanisms to account for the low overrun and long whipping times in defective creams are discussed
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